The phrase "ago developed" is not correct and usable in written English.
The word "ago" is typically used to indicate a time in the past and should not be combined with "developed" in this context.
Example: "The technology was developed last year."
Alternatives: "previously developed" or "earlier developed".
"20 years ago, developed countries missed the opportunity to transition from HFCs to a safer option.
Mr. Washington maintains that Mr. Roney long ago developed "his own big, dark sound".
Other markets long ago developed clearinghouses to settle trades and manage the resulting open positions in derivative contracts.
Walrod long ago developed a casual manner that often makes working with him seem like hanging out and shooting the breeze.
The negotiations were complicated by news reports suggesting that Mr. Klestil had long ago developed a prejudice against Mr. Haider and the Freedom Party.
Montague long ago developed computer software to design kites larger than a thousand square feet, on lines that reach hundreds of feet into the air.
Asteroids first formed at the birth of the solar system 4.6 billion years ago, developing into small proto-planets.
L.S.S.I. got its start 30 years ago developing software for government use, then expanded into running libraries for federal agencies.
The Indian subcontinent first touched against the Asian continent about 53 million years ago, developing structures that preceded the main Himalayan orogeny (mountain-building event), which began in earnest some 40 million years ago.
Twenty years ago, developing regions hosted about 70% of the world's refugees; last year, countries ranked least developed by the UN were home to 3.6 million refugees – or 25% of the global total.
Many of the major sub-divisions occurred over 10 000 years ago, developing as humans migrated into new geographic areas.
